Do you have to occasionally plug the hybrid into an electrical outlet at home, or are the batteries fully sustained by the gas engine?
If you have to plug in, what is the cost of electricity to bring the batteries back up to 100%?
I know I've said it here before, but I really am going to pursue the waste vegetable oil/biodiesel cooker for my Dodge Cummins truck. Current research shows it costs about 75¢ per gallon to make, if the waste oil is free and not including cost of equipment. I believe the emissions are considerably less harmful as well, but have not specifically researched that.
My father in law owns a resturant in SW Utah, & has gone the biodiesel route for all his farm equipment. He has enough extra fuel that he's been looking for a Cummins powered Dodge as well.